Brake shoe key



,Petented sept. 19, 1933' UNITED STATES BRAKE SHOE KEY Maurice N. Trainer, East Orange, N.' J., assignor to The American Brake Shoe and Foundry Company, Wilmington, Del., a corporation of Delaware Application April 29, 1932. Serial No. 608,174

2 claims.

This invention relates to keys for securing brake shoes to brake heads and its object is to provide a strong, substantial, spring steel key of novel form which will tightly and securely hold a new or an old shoe to a new or an old head and thereby reduce the wear between the parts and prolong the life of the parts. I Another object of the invention is to provide the key with a head which will engage the shoe and constitute a fixed stop for the key thereby centering the key in its .proper position for securing the shoe in the head and preventing the key from wearing upon the head at the top thereof and also providing a means which is always in position te facilitate removal of the key.

And a further object of the invention is to' reenforce and strengthen the key at its upper end portion which is the part most affected by the blows of a tool employed todrive the key 0 into locking position.

In the accompanying drawing illustrating a selected embodiment of the invention Fig. 1 is an elevation partly in section showing a key embodying my invention and securing a shoe in a brake head.

Fig. 2 is a perspective elevation of the key.

Fig. 3 is a transverse sectional view on the line 3-3 of Fig. 2, and

Fig. 4 is a detail view showing a modiiied form of head for the key.

Referring to the drawing 5 is a head having lugs 6, 7 and toes 8, 9; and 10 is a brake shoe having an attaching lug 11 and end lugs 12, 13. The lugs 6, 7 of the head have openings 6', 7',

and the attaching lug of the' shoe has an opening 11', and these openings'form a keyway to receive the key 14. The key is made of at spring steel of proper length and width to flt the head D and shoe and oi' suilicient thickness to provide the necessary strength. The key has a head 15, a straight upper section 16, a long bend or riser 17, a short bend or riser 18, a straight lower section 19, and a plurality of notches 20 at its lower end. The bend 17 is directed rearwardly and the bend 18 is directed forwardly of the key. When the key is inserted in the keyway of a new shoe and head and driven lightly in, as indicated inbroken lines in Fig. 1, it will bear against the upper edge portions of the top wall of the openings in the head lugs 6, 'I and the attaching lug. 11 of the shoe, and when the key is driven into final position, as shown in full lines in Fig. 1, the bend 17 fully engages the top wall of the opening in the attaching lug, and that part of the key at the (ci. isa-243) body of the straight portion 16 where the bend 17 begins fully engages the top wall of the opening in the lug 6, and that part of the key where the lower end of the bend 17 merges into the bend 18 engages the lower part of the top wall of the lug 7. A new shoe projects above the upper end of the brake head as shown in Fig. 1 and the head 15 of the key engages the upper end of the shoe when the key is in nal position and clears the upper end of the brake head. The lower end of the key is engaged by one of the notches 20 with the lower end of the head to resist any tendency of the key to move upward in the keyway or to become dislodged; but this engagement of the notch with the head will not prevent the key from being driven out or otherwise removed from the keyway. When the head of the key engages the shoe as shown in Fig. 1 it will be suiciently elevated above the brake head to permit access of a tool to engage the head of the key forl removing the key from the keyway. The head wears in service where the attaching lug rests upon the lug 7 of the brake head and the end lug 12 engages the toe 8. The upper end of the brake head is also worn by the key which has heretofore been commonly used. The result has been that the key becomes loose in the keyway due to the wear of the brake head and this permits the shoe to vibrate freely in the brake head, thereby increasing the wear of parts, and sometimes the key works out of the keyway and releases the shoe. If the key is loose when the' car is turned upside down for dumping it will fall out of the keyway and permit the shoe to fall away from the head, and if the car is not carefully inspected after the dumping operation it may travel away without any shoes. It is important therefore to provide a key which can be easily inserted and easily removed, which can be used with old shoes and heads as well as with new shoes and heads, and which will hold the shoe securely and tightly in the brake head to reduce vibration and to prevent release of the shoe. These objects are accomplished by my invention because the key is made of spring steel and is bent in a manner to insure that it will be maintained under tension in the keyway under all ordinary conditions of'shoes and brake heads. The key is driven in the keyway and the upper straight section 16 receives the greatest effect of the blows which tend to bend this part of the key and to some extent destroy its usefulness, and for this reason I reenforce this straight section of the key by iluting or corrugating it as shown at 21. I also prefer to provide the key with a iiat forged T-head, as shown in Figs. l end 2, which has a projection 15' to engage the upper end of the shoe and anoppositely disposed projection 15" which extends over the upper end of the brake head but is always spaced therefrom to permit a tool to be inserted for removing the -key from the keyway. I may bend the upper end of the key upon itself to form the head 22, as shown in Fig. i. Sufficient notches 20 are preferably provided in the key so that when the key is flrst inserted and lightly engaged in the keyway at least one notch willbe engaged with the lower end of the brake head, and when the key is driven to final position another notch will be engaged with the brake head.

I may provide any number of notches and change the form, size and material of the key to suit different conditions and within the scope of the following cl:

Leemans l l; claim.:

l. The combination with a brake shoe head and a brake shoe having intertting lugs provided with elined openings to form. e. ke of a key arranged in seid keyway and securing the shoe snugly on the brake head, said key having e. head with oppositely extending projections, one of said proiections extending over the shoe to rest upon the upper end thereof and the other projection extending over the upper end of the brake head and spaced therefrom.

2. The combination with a brake shoe head and a brake shoe having interfitting lugs provided with alined openings to form a keyway, of a key' arranged in said keyway and securing the shoe snugly on the brake head, said key having a straight upper section and said upper section being uted longitudinally'.

MAURICE N. TR.

EUG

y no 

